Distribution system planning is a key component to accomplish the service in a fast growing demand market, both from a technical point of view and from the economic costs management. In the near future, electric companies will need faster and cheaper planning tools to evaluate different scenarios and their consequences for the rest of the system and provide their clients whit safe reliable and economic energy. The objective of this paper is to review different articles about this subject trying to continue the previous work from Gonen and Ramírez-Rosado in 1986 (Gönen,1986).